The present invention relates to a removable center plug of a lavatory pop up drain assembly, commonly referred to as a "Pop-Up Plug". Specifically, the plugs of the present invention outwardly appear to be and function in a manner equivalent to OEM factory models but are convertible to special decorator models merely by use of an accessory overcap, the overcap assembly floats up and down relative to a body of the plug so as not to interfere with original seal designs. This feature accommodates all OEM models, old and new, without risk of leakage. The plugs, when converted, cover the entire OD of a flange of a pop up drain assembly in the lavatory thereby eliminating the need to change the entire assembly if the flange is damaged, discolored or if it is desired to change aesthetics, for example, from chrome to polished brass.